Tire gauge



. In-nudo@ H. N. THUNE TIRE GAUGE Filed July 28, 1927 HN Thun e @la ttozmz'ql July 30, 1929.

Patented vJuly 3o, 1929.

"UNITED STATES TIRE GAUGE.

Application filed July 2.8, 1927. Serial No. 209,014.

The present invention is directed to improvements .in tire gauges.

The primary object of the invention 1s to provide a device of this character so constructed that the same canbe set and the tire inflated to the corresponding pressure indicated upon the gauge.

Another object of the invention vide a gauge for this purpose constructed 1n such .manner that when 'the pressure has reached a predetermined point air will escape from the gauge tol prevent over-inflation, and at the same time give an audible signal to indicate that-the proper pressureis built up inthe tire. y

Another object of the invention is to provide a device of this character so constructed that it can be used in connection with wheels of various. kinds, the construction and arrangement being such that air may be introduced into the tire without operating the gauge, if desired.

v In the accompanying drawing: Figure 1 is a longitudinal sectional-view through the device. l Figure 2 is a sectional view on line 2--2 of Figure 1.

Figure 3 is a perspective view of the lever. Figure 4 is a fragmentary side elevation. Referring to the drawing, 1 designates a hollow head having a cap 2 threaded thereon and confining a -rubber plate 3 provided with a valve seat 4, and cooperating with said seat is a valve disk 5 having a valve stem engag- 'ing lug 6 carried thereby.

min'ates in a hollow neck pivotally mounted a lever 8, said lever having its forward end provided with a head 9 yadapted'to bear against4 the disk 5, said head being resiliently maintained engaged upon the disk by the spring'lO which has one end fixed to the lever and its other end engaged with the interior wall of the head 1.

The neck 7 has a threaded lextension 11 protruding therefrom and provided with an axial opening 12 in which is slidably engaged va stem 13, said stem fitting in the opening somewhat close, but not too close, to permit air to pass through the opening.

Threaded upon the extension 11 is a coupling 14 having gages the valve vdisk 17 vfixed to the lower end of the stem 13,A and whichserves asa closure for the air entrance end ofthe opening.

`which an air conducting hose,

is to pro- The head 1 ter- 7 and in which is.

' outer ends adapted to a4 chamber 15 therein and in which is located al coil spring 16 which en- 'p A. Secured thereto a plate nipple 18 leads from the coupling 14 and to not shown, is secured for admitting compressed air to the gauge.

The rear end of the neck 7 is provided with ane'Xteriorly and interiorly threaded annulus.19, and having its inner end threaded eX- teriorly thereon is a barrel 20, while the concentrically arranged tube 21 has its inner end threaded interiorly of said annulus, the annulus maintaining the barrel and tube in spaced relation. A portion of the barrel is shaped to define an indicator 22.

The tube 21 4h as threaded therein the eXtension 23 of the plug 24, said plug having a A threaded periphery 25 for engagement with the tubular member 26 movable in the space between the barrel 20 and tube 21, the tubular member -26 having a cap 27 threaded thereon and provided with a threaded opening 28, the purpose of which will later appean Graduations denoting pounds pressure are marked upon the tubular member 26, as shown in Figure 4, to cooperate with the pointer 22. gasket 20 is provided in the outer end portion of the'barrel to prevent sediment, grit and moisture from getting between the barrel and tubular member 26 and into the gauge.l

In the forward end of the tube 21 is mounted av hollow piston 29, the forward end of which is closed by a disk 30 having a seat 31 and with which cooperates a ball valve 32, said ball being confined in the cage 33, there being acut washer 34 fixed thereto. An air inlet 35 is formed in the rear wall of the neck 7 to permit air to enter the piston 29 seating the ball valve in the seat 31. Having its outer end threaded in the opening 28 is a cylinder 36 having slots 37 formed therein and slidable on this cylinder is an outer collar 38 which is connected'to an inner collar 39 by a coil spring 40, the collar- 38 being ixed to l the plunger 41 slidable in the cylinderf36 by a pin 42 which is limited in its sliding movement in the slots 37 of the cylinder 36. The plunger 41 is provided with a pair of resilient arms 43 having latches 44 from their meet and be released by the cams 45 mounted in the outer collarl 39. The cylinder 36 is further provided with a air. of slots 46 in which the latches 44 rest and normally interlock with the rear walls thereof. The inner end ofthe cylinder has 47 having openings 48 knormally closes the outer end of the cylinder 36 and when seated will obviously prevent the entrance of dust, grit, andmoisture. A coil spring 51 encircles this stem and has its inner end bearing against the plunger 41 and its other end engaged-with an annular shoulder 52 formed interiorly of the cylinder.

Encircling the cylinder and collars 38 and 39 is a coil spring53 which has its outer end engaged with the extension 23 of the plug 24 and has its inner end engaged with the outer end of the coil spring 54 which is of less strength than the spring 53, the inner end of the spring 54 being engaged with the disk 30. Since the spring 54 is of less strength than the spring 53, it will allow the piston `to move more for each pound of pressure than thespring 53 would allow it to move. `This will allow for singular graduation upto a certain pressure as theI cap 27v which brings the cylinder 36 with it in or out and the barrel 26 will have to be turnedv .around more for each pound, than when at t-he higher pressure when the spring' 53 takes effect and will have to yield.

The plug 24 is provided with an axial bore 55 in order that the cylinder 36 may slide `therein during the adjustment of the gauge.

It will be a parent that when the head 1 is engaged Wit an inflation valve o -a tire that the valve stem thereof will engage the lug 6, thus unseating the disk 5 and rockin the lever 8, whereupon the inner end thereo will engage the stem 13 to unseat the valve 17 to permit air to pass'through the openin and into the tire. Obviously,- When the ead is removed from engagement with the tire inlation valve stem, the spring 16v and air pressure provided in the chamber 15 will seat the valve 17 to cut olf the air supply. Assuming that the tire is under-inated and it is desired to inflate the same to the predetermined pressure, .the cap 27 is rotated which feeds the member 26 and cylinder` 36 inwardly or outwardly, owing to its threaded connection with the plug 24, until the desired pounds graduations coincide with the indicator 22. As the air-pressure builds up in the tire it will back up into the hollow neck 7 and pass through the inlet 35 and will seat and hold the valve 32 seated, thus exerting pressure upon the piston 29 to force the same outwardly, compressing the springs 53 and 54 until t e plate 3() contacts with the outer collar 39 and forces the same outwardly against the tension of the Vspring 40. As soon as the cams 45 fully engage the latches 44 they will be released and the spring 40 will expand, relieving the pressure against the piston and thereby forcing the co1lar`38 away from the co1- tube havin lar 39. The collar 38 carries with it the plunger 41 which is connected to the collar 38 y pins sliding in the slots 37 of the cylinder 36 and this forces the spring 51 to yield and the plunger pushes the'stem carrying the cup shaped head 50 out for free escape of air to atmos here witha hissing sound to indicate that tli in the tire. Quick movement' of the piston caused by release of the spring 40 will now cause the valve in the piston to engage the plate 47 of the cylinder and the valve 32 will e suddenly moved to a Wide-open position. As the air passes into the cylinder 36 it will exert pressure upon the plunger as it passes thereby, thus aiding the compressing of the sprinof 51 which is a comparatively weak one, but of suflicient strength to-force the plunger 41 and collars 38 and 39 forwardly and reseat the same as soon as the gauge is removed from the tire inflation valve. The springs 53 and 54 will return the piston 29 to its normal position and the stiffness of the spring 40 will move the inner collar inwardly by the spring 51 forcing the plunger 41 inwardly in order that the latches 44 will again snap into engagement with the slot46 of the cylinder 36. If it is desired to ascertain the air pressure ina tire the head 1 is en aged with the tire valve to open the seat 4, ut at a pressure which will. not rock the lever 8 sufficiently to open the valve 17. In case the tire has been previously over-inflated the gauge will open to permit the escape of excess pressure. Of course, if it is then desired toinate the tire the head is pressed with sufficient force upon the tire valve to cause the lever to open the valve.

Having thus described the invention, what claim is:v

1. A 'device of the class described comprising a tube having a hollow piston slidable therein, springs to yieldably hold said piston against compression, a valve in the piston, a cylinder ad]ustabl mounted in thetube, a stem carried by t e plunger and having a head thereon for normally closing the outer end of the cylinder, means for interlocking the plunger with the-cylinder, and means associated with the cylin'der for engaging the valve of the piston to permit air to pass by the plunger when the said plunger and valve means for conducting air into the tube for action upon the piston, a tubular member 'threaded upon the tube, a cylinder in the a plunger slidable therein, latches carrle'd by the plunger for interlocking engagement with the c linder, and means controlled by the outwar movement of the piston for releasing the latches to relieve pressure against the pistonby release ofyielde proper pressure has been built up 12o tubeand having a valve carried thereby,

able means and simultaneously unseat the 'valve of the piston to permit air to pass therethrough into the cylinder.

3. A gauge of the class described comprising a tubular member, means for conducting air into the member, a piston slidable in the member and having a valve carried thereby, a plug engaged in the end of the member, a spring in said member between `said piston and plug to control movement of the piston, and being securely fastened to a cylinder mounted in the tube and slidable in the plug, a plunger slidably mounted in the cylinder and provided with a transverse pin to hold and relieve yieldable means, by its connection to the outer collar and slidable 1n slots in the cylinder to control movement of the plunger, a head carried by the outer end of said plunger for normally closing the outer end of the cylinder, said plunger having latches carried thereby for normally interlocking engagement with the cylinder, a collar slidable upon the cylinder and having cams carried thereby for engagement with the latches to release the same to permit the plunger to slide to relieve compression of yieldable means against said collar and'piston, and means carried bythe cylinder for unseating the valve of the piston when the cams of the collar re-v lease the latches.

4. A gauge of the class described comprising a barrel, a tubular member disposed concentrically with respect to the barrel and engaged Awith the annulus, a hollow piston sli able in the tube and having a valve carried thereby, means for conducting air from the neck into the member, a vplug threaded in the end of the member, the barrel and tubular member having cooperating means for indicating pounds pressure, a cylinder slidable in the plug and having inner and outer collars associated therewith, yieldable means connecting the collars, thel cuter collar and plunger having connection by a pin, the inner collar having cams carried thereby, a plunger slidable in the cylinder and having a stem provided with a head for normally closing the outer end of the cylinder, a spring encircling thestem and interposed between the plunger and shoulder in the cylinder,y resilient arms carried by the plunger and having latches carriedthereby for normally interlocking engagement with the cylinder, a.

plat-e carried by the cylinder for engagement with the valve for unseating the same when the piston is forced outwardly by air pressure, and means carried by the piston for moving the inner collar outwardly to lcause the cams carried thereby to release the latches to permit the expansion of said yieldable means, causing a quick move of the piston andv causing movement of the plunger and its stem outwardly to permit the' head to disengage the outer end of the cylinder, and springs controlling the movement of the piston.

In testimony whereof `l ax my signature.

HELE/IER N, THUNE. [n s] 

